The present application relates to methods for producing semiconductor devices, and particularly to a method for producing a semiconductor device including a patterned organic semiconductor layer.
Recently, semiconductor devices including organic semiconductor layers as active layers have attracted attention as semiconductor devices that can be produced with large area at low cost. One problem with the production of such organic semiconductor devices is that, when an organic semiconductor layer is patterned for device isolation by etching using a photoresist as a mask, solvent contained in the photoresist damages the organic semiconductor layer, thus impairing the electrical properties thereof.
Accordingly, a method has been proposed in which a protective film is formed on an organic semiconductor layer using a material having solvent resistance before a mask pattern is formed on the protective film using a photoresist. In this case, the protective film is etched using the photoresist as a mask before the organic semiconductor layer is etched with oxygen plasma (see Japanese Unexamined Patent Application Publication No. 2006-41317 (particularly, paragraphs 0057 and 0058)).
In addition, a method has been proposed in which an organic semiconductor layer is formed in a predetermined pattern by printing, such as inkjet printing, to avoid the effect of solvent contained in a photoresist on the organic semiconductor layer. In this case, if a protective film containing, for example, a siloxane compound is formed so as to cover the printed pattern of the organic semiconductor layer, it prevents the organic semiconductor layer from being damaged in the subsequent process (see Japanese Unexamined Patent Application Publication No. 2008-300580 (particularly, paragraphs 0174 to 0176)).